The Infusinator Air Snorkel Kit is used to connect the air manifold to the surface air.  Since there are multiple variations to a manifold design, various components are provided to meet your needs.  The kit also includes an intake filter which is used to keep debris and insects from entering into the air intake.  It also acts as a muffler to reduce the overall sound of your system.

Note: Some cutting of the pipe is necessary to customize for your setup.